The raising of horses cattle, sheep, goats and other livestock typically requires that the animals be kept, fed and watered in outdoor areas for large parts of a year, such as, for example, open range, pasturage areas or barnyards or feed lots. This requires the provision of fresh, liquid water to the animals to insure their survival, growth and well-being, including the prevention of disease and the provision of proper nutrition. Such water is typically provided to the animals by means of stock watering facilities including, for example, stock water tanks, automatic livestock waterers or various forms of reservoirs or ponds.
A recurring and severe problem in providing such water to livestock is in keeping the water from freezing, particularly in the cooler and cold seasons and environments, that is, early spring and late fall and in some instances in winter or even in summer at higher altitudes. This problem is compounded because the livestock need easy and direct access to the water, so that the tops of the tanks, the ponds and other forms of reservoir, are open to the winter air and suffer significant heat loss due to conduction, convection, and evaporation.
The systems and methods of the prior art to prevent freezing of livestock water range from recirculating pumps to keep the water moving to heating elements to directly heat the water above the freezing point. Keeping water moving, however, such as with recirculating pumps, is only successful down to temperatures near or slightly below freezing, and if temperatures fall below 15-20 degrees Fahrenheit, dependent upon wind chill and other factors, recirculating devices are inadequate. Therefore, most stock tank freezing prevention systems and methods rely upon direct heating of the water by means of electrically or fossil fuel powered thermostatically controlled heating devices immersed in the water. Some de-icers are floating, some are mounted on the bottom of the tank or reservoir or pond, and some are located somewhere between the surface and the bottom of the water, but all, whether electrically powered or powered, for example, by propane or natural gas, consume large amounts of power and are correspondingly expensive to operate. Electric tank de-icers, for example, are effective and reliable, but can cost several hundred dollars a month to operate. In addition, the use of electrical or other fossil fuel powered heating elements is environmentally detrimental and results in a significant carbon footprint.
Other methods of the prior art have attempted to at least alleviate the above discussed problems. For example, various designs of proprietary watering devices have a smaller water access opening, thereby reducing the amount and area of water exposed to the environment. Another device provides a cover over the entire surface of the water wherein the cover has one or more openings, each covered by a floating element, so that any one of the floating elements may be pushed down by an animal to allow access to the water therebeneath, as illustrated U.S. Pat. Nos. 5,437,244, and 4,518,281. Such methods, however, are mechanically complex and correspondingly expensive, with resulting losses in reliability, and are unsuited for use with many animals, a number of which, for example, inherently will not or cannot operate a mechanism to gain access to water.